Exemplary embodiments of the invention relate to a front end module
European patent document EP 1 849 686 A1 discloses a front end module with a pipe formed by means of fluidic internal pressure, which has two neckings axially spaced apart, into which an injection molded component made from plastic is injected. For this purpose, rings are provided surrounding the pipe and from which the injection molded component, referred to as columns, extrudes in one piece vertically downwards. Both separate injection molded components are adjacent to a receiver for the engine radiator. A respective installation space for lighting units is connected laterally. The composite component made from the metallic pipe and the injected plastic components form the front end module. The hold of the two columns on the pipe, which results from the shrinking of the plastic on the pipe, is, however, insufficient with respect to higher mechanical loads, such that the columns are able to rotate around the pipe relatively easily and can also slip axially inside the extension of the neckings.
Exemplary embodiments of the invention are directed to a front end module of this kind such that an improved hold of the injection molded components on the cross-member is achieved in a simple way.
In accordance with the invention there is a separate connection of at least two of the injected plastic components, with which the indirect connection is excluded by the cross-member, achieves a force distribution that impedes a release of the respective plastic component part on the cross-member, if it does not prevent it completely. For this purpose, during a loading of one of the plastic components, a moment of inertia is produced in the other plastic component around the cross-member axis due to the connection, the moment of inertia in turn exerting a counter force on the loaded plastic component, which causes a torsional stress in the connection element of the connection and thus counteracts the loading and therefore improves the hold of the one plastic component.
In an advantageous development of the invention, the cross-member is bent, wherein at least one of the plastic components is arranged in a bending region of the cross-member over a longitudinal section. For this reason, the plastic components have a particularly strong hold on the cross-member, as the plastic component set in the bending region is no longer able to move axially or radially or at most when exerting very large forces. In a further advantageous development of the invention, the profile cross-section of the tubular cross-member is formed to be non-circular at least locally, wherein at least one of the plastic components is placed on this non-circular position. For this reason, the plastic component also has an improved hold in the circumferential direction of the cross-member, wherein this is set to be non-rotatable on the cross-member. With the additional arrangement in the bending region, the plastic component or the plastic components that are connected to one another has a particularly good hold on the cross-member.
In a further advantageous embodiment of the invention, the connection of the plastic components is firmly formed. This simplifies the formation of the connection considerably, as no connecting elements are required at all and only a single cavity for the plastic components to be formed and to be connected is necessary. The plastic components can be advantageously produced at the same time in a single work step and with a single tool and thus are produced with procedural economy. Additionally, the firmness of connection provides an increased stability for the plastic component arrangement. It is conceivable, alternatively or additionally to the firmness of connection, to provide a positive connection between the components. For this purpose, the components can be injected at different points in time, such that the already-set component is equipped with positive connection elements such as elevations and troughs, which are positively surrounded by still liquid or viscous injection molding of the other component or of the other components. Due to the molding heat of the still liquid injection molding, it is possible that the already set component can be melted easily such that a firm connection can also be achieved at the same time as the positive connection.
The cross-member can likewise have positive connection elements, which are surrounded by the injection molding of the formed component or which form a supporting operative connection to the injection molding during injecting. These can, for example, be formed by a reshaping of the hollow cross-member, in particular by means of fluidic internal pressure or by a combination of the inner pressure with a mechanical press processing, for example by means of a stamp. The cross-member can also preferably have a shape deviating from a rotationally-symmetrical cross-sectional outline, for example an oval or a square shape. This is also preferably found where the injection molding fits against the cross-member, such that the injected plastic also has an anti-rotation feature and thus an improved hold on the cross-member due to the cross-sectional shape.
According to a particularly preferred development of the invention, the injection molded components include two columns thatthe extrude perpendicularly downwards and are spaced apart axially. These border the side of the engine radiator receiver and are axially spaced apart from the ends of the cross-member. The cross-member has injected longitudinal and transverse ribs, which together form a net surrounding the cross-member and connect the columns to one another in the region of the cross-member. Due to the formation of a net, which surrounds the cross-member in the space between the columns, an extremely rigid connection is created with a low installation space requirement and material usage, the connection not only being rigid in all directions but also stiffening the entire plastic complex and the cross-member. Due to the extremely rigid connection, a secure hold for the plastic components on the cross-member is created even in the case of high mechanical forces.
According to a preferred development of the invention, multifunctional components are created due to the formation of the injection molded components as columns, the multifunctional components not only forming a frame for the engine radiator receiver but also forming a partial frame for the lighting units from the outside in, on which fixing positions for the lighting unit are formed in one piece. Furthermore, parallelogram-shaped receivers, which are similarly formed in one piece, for the crash boxes and/or an insert device in the lower side member and/or a hanging eyelet for the auxiliary heating system and/or for the washing water container and/or for the Z-support, can be formed on the columns.
According to a further preferred embodiment of the invention, the thus already highly integrative character of the front end module is further increased by the ribs between the columns being outlet points for multiple functional configurations of the plastic injection molded complex. These are thus connected in one piece to a sealing frame for the engine radiator and/or to fixing elements for the proximity control system and/or for a deflection plate to prevent intake of snow and/or for the engine radiator and/or to levelling elements for a bumper and the engine radiator and/or to guiding walls for the air intake and/or to receivers for engine hood bumpers and/or to a hanging device for a support strut to support the engine hood and/or support plates for the upper edge of a body component.
Furthermore, the ends of the cross-member could preferably have transverse and longitudinal ribs that are sprayed on and connected to one another, which bear receivers for engine hood bumpers in one piece and/or for the fixing of a handling device to transport and position the front end module in the installation. For installation space and/or weight-saving considerations, these plastic coatings can be formed separately from the plastic injection molded complex detailed above. It is, however, conceivable for these plastic coatings to likewise be connected to the plastic injection molded complex in one piece for an improved hold on the cross-member.
In a further preferred embodiment of the invention, the cross-member has fixing elements for the engine hood lock. These are represented in the form of holes, by means of which the lock can, for example, be screwed on. The holes can be created to be precisely positioned and with a highly precise hole pattern during the reshaping procedure of the cross-member, which occurs using inner pressure reshaping. For this purpose, punching stamps are integrated into the reshaping tool, which are not only able to punch out slugs from the tubular cross-member but also close the created holes in a way that seals them using high pressure. This is achieved by a conicity of the stamp, which is connected to the cutting edge and is immersed in the hole. The plastic is injected during the reshaping procedure or immediately after it, the plastic forming the partial high-filigree plastic components after setting. On completion of the reshaping, the inner pressure is reduced to a support pressure, such that a collapse of the cross-member due to the incidental injection molding pressure is prevented.